Reaction product of alkylated hexamethylolmelamines and polyanhydrides



United States Patent 3,422,076 REACTION PRODUCT 0F ALKYLATED HEXAMETHYLOLMELAMINES AND POLYANHYDRIDES John Christos Petropoulos, Norwalk, and Jerry Norman Kora], Stamford, Conn., assignors to American Cyanamid Company, Stamford, Conn., a corporation of Mame No Drawing. Filed Aug. 12, 1965, Ser. No. 479,304 US. Cl. 260-78.4 4 Claims Int. Cl. C08g 9/36 ABSTRACT OF THE DISCLOSURE A process for the production of a product which is soluble in a mixture of xylene and Cellosolve acetate and comprises alkylated methylol rnelamine units linked together by anhydride units and the products, per se, are discussed.

The use of alkylated hexamethylolmelamines as additives and/or cross-linking agents with, for example, alkyd resins and epoxy resins, or as flow-promoters for urea-formaldehyde and triazine-aldehyde resins and the like is well known in the art. Although these alkylated hexa-methylolmelamines are excellent in regard to increasing the gloss, hardness, etc. of these resins, they tend to decrease the viscosity of the resin to such an extent that the resultant system may not be useful for all the applications generally accorded the resin per se. That is to say, an alkylated hexamethylolmelamine, when added to a resin, results in a product which has a lower viscosity than that of the resin per se. Therefore, the resultant system lacks utility in applications wherein the high viscosity of the resin is a prerequisite.

We have now found that various products can be produced by reacting an alkylated hexamethylolmela-mine with a polyanhydride, which products possess all the desirable properties mentioned above in regard to the alkylated hexamethylolmelamines per se, but do not exhibit a marked decrease in the viscosity of the resins with which they are blended. These novel products are also effective per se as cross-linking agents and further permit the formulation of coating compositions which have solids contents, at a useable spray viscosity, lower than the monomeric alkylated hexamethylol melamines. They may also be cast into hard, glossy films which are free of defects (craters etc.).

It is, therefore, an object of the present invention to provide a novel process for the production of alkylated hexa-methylolmelamine reaction products.

It is a further object of the present invention to provide a process which comprises reacting a polyanhydride with an alkylated hexamethylolmelamine which, on the average, is not fully alkylated, to produce a polymeric alkylated amino resin.

It is a further object of the present invention to provide novel polymeric alkylated amino resins.

THE NOVEL METHOD Our novel method, as mentioned above, comprises reacting a polyanhydride, or a mixture of a polyanhydride and up to 50%, by weight, based-on the weight of the mixture, of a cyclic monoanhydride, with an alkylated hexamethylolmelamine.

The alkylated hexamethylolmelamines referred to herein are generally in the form of a mixture of com pounds, which mixture of compounds, on the average, is not fully alkylated. These mixtures are generally produced by reacting hexamethylolmela-mine with an aliphatic alcohol. For purposes of this invention alcohols of from 14 carbon atoms are sufiicient. When the "ice alcohol is reacted with the hexamethylolmelamine, the resultant product is a mixture of alkylated compounds. While the production of pure alkylated hexamethylolmelamines is theoretically possible, the recovery of such materials has proven to be virtually impossible. As mentioned above, in preparing these compounds, the hexa'methylolmelamines are generally first prepared and then reacted with the appropriate alcohol to produce the alkylated derivatives. The hexamethylolmelamine is, however, in fact, itself not a pure material, but instead has a degree of methylolation averaging between about 5.8 and 6.1 methylol groups per mol of melamine. Theoretically, at least, melamine can only accept, as a maximum, 6 moles of formaldehyde per mol of melamine to form hexamethylol melamine. However, analytical determinations have frequently shown that the degree of methylolation sometimes exceeds the 6:1 ratio, and this seeming departure from theory is not readily understood nor is there any attempt to explain it set forth herein. When the degree of methylolation is less than six, however, i.e. 5.8 or 5.9, it must be concluded that there exists in the compositions, some hexamethylolmelamine and various other minor proportions of the lesser methylolated derivative, such as the pentamethylolmelamine. Therefore, when the material is alkylated, the resultant product is also a mixture of alkylated polymethylolmela-rmines. We have found that compositions of this type which contain, on the average, from about 3 to 5.8, alkyl groups are useful in the instant process in that the reaction occurs via the nonalkylated hydroxyl groups remaining after alkylation. As a consequence, when reference is made to alkylated hexamethylolmelamines as starting materials in the process of the present invention, it should be understood that a mixture of the alkylated polymethylolated melamines is intended, althoughpure compounds may also be used.

Examples of methods for the production of these alkylated hexamethylolmelamine compositions are set forth in U.S. Patents Nos. 2,918,452, 2,998,410 and 2,998,411. Further useful compositions are set forth in our copending application, Ser. No. 326,347, filed Nov. 27, 1963.

Any material which contains more than one anhydride group may be used as the second reactant in our novel process. That is to say, compounds, mixtures of compounds, resins, polymers and the like may be used in our novel process.

Examples of polyanhydrides which may be utilized include benzophenone dianhydride, pyromellitic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-l-naphthalene succinic dianhydride, cyclohexane dianhydride, cyclopentane dianhydride, and various polyanhydrides produced by reacting maleic anhydride, itaconic anhydride, etc. with such materials as styrene, vinyl toluene, etc. as disclosed and claimed in copending applications Ser. Nos. 442,- 207 and 442,209, filed Mar. 23, 1965, and 440,292, filed Mar. 16, 1965. As mentioned above, we may also utilize various homoploymers and copolymers, which contain at least two available reactive anhydride groups. Polymers of this type include, polymaleic anhydride, styrene-maleic anhydride copolymers, vinyl acetate-maleic anhydride copolymers, and the like. Cyclic monoanhydrides which may be used include phthalic anhydride, maleic anhydride, succinic anhydride and the like and derivatives thereof, in amounts up to 50% in admixture with the above enumerated polyanhydrides.

The concentration of the melamine to polyanhydride should range from about 5:1 to about 1:5, preferably from about 2 /2:1 to about 1:1 /2, respectively.

The reaction is conducted in the absence of a catalyst and in the absence or the presence of a solvent such as a xylene-Cellosolve acetate mixture, a toluene-Cellosolve 3 acetate mixture, at dimethylformamide-xylene mixture and the like.

The temperature at which our novel method is conducted ranges from about 95 C. to about 150 C., preferably 110140 C.

mixture of xylene/Cellosolve acetate has a Gardner-Holdt bubble viscosity of T-U.

Example 2 A suitable reactor, fitted with a stirrer and thermometer,

O 5 is charged with 125 parts of the methylated melamine of temperatures .below about 95 fi g Example 1 and 100 parts of 3,4-dicarboxy-1,2,3,4-tetrareacotlon occurs .Whlle at temPerEMureSdSu if T 1a hydro-l-naphthalene succinic dianhydride. The reaction i produq Is i W 101 i mixture is stirred and heated over a 2 /2 hour period, at msutficlent m propertlebs fi uses 130 C. A hard, homogeneous mass is obtained. The harem macho? must 6 to g g 10 product is removed from the reactor and when cooled to least 5 mmutes and Preferably i 1 F room temperature forms a brittle, glass-like material. The 5 hours A'tmosphenc pressure u .2 ai resin has an acid number of 145. A 60% solution in a atmospheinc f howfever on mm 65/ 35 solvent mixture of xylene/Cellosolve acetate has a the volatlleswhlch result rom the reac lon are 1 on y GardnepHoldt bubble viscosity of P. released at high pressure.

The reaction may be carried out in the presence of air, Example 3 Pxygen, any Inert f be utlhzed F a w A suitable reactor, fitted with a stirrer and thermom- In order to prevent contamination and llIldtESliEd side reeter, is charged with 1410 parts of the methylated actlonsamine of Example 1 and 577 parts of a styrene-maleic THE NOVEL PRODUCTS anhydride 65/35 copolymer. The reaction mixture is As mentioned above, our novel products are polymeric stlrred and heated to 120 C. over a period of 45 minin nature and generally consist of alkylated methylolmelt s and held at that temperature for an additional 4 2 amine units linked together by anhydride molecules. The h urs. The resin is cooled and a brittle, amber mass 18 novel products are clear, glassy, light yellow to amber in Obtained. The resin has an acid number of 41. A 60% socolor, brittle, resinous products. They are thermoplastic lutlon in a 65/35 solvent mlxture of xylene-Cellosolve materials which melt at about 20 C. to 40 C. and have acetate has a Gardner-Holdt bubble viscosity of Q. molecular weights ranging from about 1,000 to about Examphs 4 f A suitable reactor, fitted with a stirrer and thermom- A mentioned above, our novel products are useful 01 eter, is charged with 84.5 parts of the methylated mel- 311 the apphcailons known regard to alkylated amine of Example 1 and 47.5 parts of a styrene-maleic m?t.11y1o1me1amme For example y may anhydride (65/35) copolymer. The reaction mixture is i as crossfhnkmg agepts for alkyd .acryhc heated over a 15 minute period to a temperature of 123 resms epoxy p and the i They may uuhzed as C. and then the temperature is raised to 135 C. over the Such for lammaflng and coatmg as W611 In other areas next twenty minutes. The resultant viscous mass is cooled Where amlnol:eslns find and the acid number of the resin is 53. The Gardner- The iollowmg examples are Set with 9 9 of Holdt bubble viscosity of a 50% solids solution, in a 65/ illustration only but are not be construed as limitations 35 mixture of Xylene and Cellosolve acetate is H- on the instant lnventlon except as set forth at the ap Exam 1e 5 pended claims. All parts and percentages are by Weight P 40 A sultable reactor is charged with 1128 parts of the unless otherwise specified.

methylated melamine of Example 1, 420 parts of a Example 1 styrene-maleic anhydride (75/25) icopolymer and 200 A suitable reaction vessel, fitted With a stirrer and parts of phthalic anhydride. The reaction mixture is thermometer, is charged with 1865 parts of a mixture of heated to 120 C. over a 40 minute period and held at methylated hexamethylol melamines having an average this temperature for 1 hour and minutes. The viscous of 5.0 methyl and 5.9 methylol units, and 770 parts of 45 mass is cooled and the resultant resin has an acid number 3,4-dicarboxy-1,2,3,4-tetrahydro-l-naphthalene succinic of 73. The Gardner-Holdt bubble viscosity of a 60% dianhydride. The reaction mixture is stirred and heated solids solution, in a 65/35 solvent blend of xylene/Celloover a 2 hour period, at 128 C. A viscous, homogeneous solve acetate, is R-S. liquid is obtained. The reaction mixture is held at this Following the procedure of Example 1, various other temperature for 65 minutes. The product is removed alkylated hexamethylolmelamines are reacted with various from the reactor and when cooled to room temperature other polyanhydrides to produce the novel compositions bec mes a r glass-like material. e in has an of the instant invention. The results of these reactions acid number of 63. A solution in a /35 solvent ar t f th h i b l i T bl I,

' TABLE I Product Ex. Melamine compound Polyanhydride Acid No. Gardner-Holdt 5 Soluble 6 Butylated hexamethylol melamine- Pyromelliticdianhvdn'de 50 X-Y Dlmethyliormamide.

310 (ave.) butyl and 5.8 (ave) methyl- S. 7 "i562? T e reactio lJIOdllCt of styrene and 45 U-V Xylene/Cellosolve acetateitaconic anhydride at C. (n1.p., (55/35. 266268C.). 8 do 3,4-dicarb0xy-1,2,3,4-tetrahydr0 6 (and 55 '1 D 7)-methyl-l-naphthalene-succhlic dianhydride. l 9 Ethylated hexamethylol melamine- 3,4 dicarboxy-L2,3,4-tetrahydro-6 52 T-U Do.

4.9 (ave) ethyl and 6.1 (ave) methyl- (and 7)-butyl-1-naphtha1ene sue 01 groups. cinic dianhydrlde. 10 .do 3,4,7,8-phenanthrene-tetracarboxylic- 43 R-s D 3,4,7,8-dlanhydride-1,2,3,4,5,6,7,8- octahydro (phenanthrene dianhydridc). 11 Same as Ex. 1 Benzophenone dianhvdride 48 X Dlmethyl formamlde. 12 do Oyclohexane dianhydride 65 V-W Do, 13 "do Copoly'mer of vinyl acetate (75) and 55 X D maleic anhydride (25). 14 do P01y(maleic anhydride) Z-Z D0.

1 Produced by reacting maleic anhydride and vinyl toluene at C.M.P.:100 C.

Produced by reacting maleic anhydride and butyl vinyl benzene at 115 C.-M.P.=100 C.

Produced by reacting maleic anhydride with divinyl benzone at 95 C.

5 In the corresponding solvent.

We claim:

1. A composition consisting essentially of an alkylated hexamethylolmelamine having, on the average, from about 3.0 to 5.8 alkyl groups and 5.8 to 6.1 methylol groups and a polyanhydride, said composition being produced at a temperature ranging from about 95 C. to 150 C. for at least about 5 minutes, the ratio of melamine to polyanhydride ranging from about 5:1 to about 1:5, respectively, being characterized by solubility in a 65/35 mixture of xylene and Cellosolve acetate and 10 comprising alkylated methylolmela'mine units linked together by anhydride units.

2. A product according to claim 1 wherein the alkylated hexamethylolmelamine is a methylated hexamethylolmelamine.

3. A product according to claim 1 wherein said polyanhydride is 3,4-dicarboxy-1,2,3,4-tetrahydro 1 naphthalene succinic dianhydride.

4. A product according to claim 1 wherein said alkylated hexamethylolmelamine is a methylated heXamet-hylolmelamine and said polyanhydride is 3,4-dicarboxy-1,2,3,4- tetrahydro-l-naphthalene succinic dianhydride.

References Cited UNITED STATES PATENTS 3,211,579 10/1965 Reiter 117-138.8

JOSEPH L. SCHOFER, Primary Examiner.

C. A. HENDERSON, 1a., Assistant Examiner.

US. Cl. X.R. 

